Printing mechanism for business machines



Feb. 1, 1966 THEVls PRINTING MECHANISM FOR BUSINESS MACHINES 2 Sheets-Sheet 1 Filed March 4, 1964 W VE N TOR o.u f H 1 1,;

A TTORNE Y Feb. 1, 1966 P. THEVIS 3,232,223

PRINTING MECHANISM FOR BUSINESS MACHINES Filed March 4, 1964 2 Sheets-Sheet 2 IN VE N TOR United States Patent 3,232,223 PRINTING MECHANISM FOR BUSINESS MACHINES Paul Thevis, Oberndorf (Neckar), Germany, assignor to Olympia Werke A.G., Wilheimshaven, Germany Filed Mar. 4, 1964, Ser. No. 349,397 12 Claims. (Cl. 10194) When present invention relates to a printing mechanism for calculators, accounting machines, and similar business machines, and more particularly to a printing mechanism in which ordinal printing wheels are first set to selected digital positions, locked in the set positions, and moved to a printing position.

In known printing devices of this type, printing wheels are mounted on a common shaft which is actuated for moving the entire set of printing wheels to a printing position. This construction has the disadvantage that the shaft and hubs of the printing wheels are damaged by the repeated impacts which produce play so that the printing wheels do not always print in exactly the same position causing an irregular appearance of the printed number.

The printing devices according to the known art use locking means which engage portions of the printing wheels spaced from one operative printing portions by which the imprints are produced, so that the force of the actuator is not directly transmitted to the operative printing portion.

Furthermore, printing devices according to the prior art do not lock the printing Wheels against axial movement so that the spaces between the digits of the printed member are not exactly the same.

It is one object of the present invention to overcome the disadvantages of known printing devices for business machines, and to provide a printing mechanism which produces accurately spaceid correctly placed uniform imprints of numbers.

Another object of the present invention is to provide in a multi-order printing mechanism, individual actuators for each printing wheel of the mechanism.

Another object of the invention is to lock each printing wheel individually during movement to and from the printing position and in the printing position, and to release the printing wheels only while the same are being set to selected digital positions.

Another object of the invention is to provide individual actuators for printing wheels which lock each printing Wheel individually against axial movement While moving to and from the printing position.

Another object of the invention is to provide actuators directly engaging the operative printing portions of individual printing wheels so that no part of the printing wheel is subjected to bending moments.

Another object of the invention is to reduce the mass of the printing wheels, to increase the printing speed, and to reduce the printing time by provision of actuators which directly engage the operative printing portion of the respective printing wheel.

With these objects in view, the present invention relates to a printing mechanism for calculators, accountin machines, and similar business machines. One embodiment of the invention comprises an ordinal set of printing wheels turnable between digital positions and having digital printing portions, and an ordinal set of actuators respectively correlated with the printing wheels.

Each actuator is movable relative to the correlated printing wheel between an inoperative position permitting turning of the printing Wheel to a selected digital position in which a corresponding printing portion is operative to produce an imprint, and a locking position engaging 3,232,223 Patented Feb. 1, 1966 "ice the respective operative printing portion for locking the printing wheel against turning movement.

Each actuator is movable with the locked printing wheel to move the same to the printing position in which the operative printing portion is subjected to direct pressure by the correlated actuator.

In a preferred embodiment, the portion of the actu-.

ator which engages the printing Wheel, has lateral prongs located on opposite sides of the printing wheel to prevent;

axial displacement of the same.

Each printing wheel has an outer gear segment cooperating With a transfer wheel in a transfer position so that the transfer wheel of the calculator sets the respective printing wheel to a printing position for printing a selected digit. Each printing member also has an inner gear in the region of the printing portions and printing faces, and this inner gear is preferably engaged by the actuator in the locking position so that the respective printing wheel is locked in an accurately set printing" position.

Since the actuator engages the portion of the printing wheel which is pressed against the surface receiving the imprint, only this poriton is subjected to the pressure produced by the actuator, and the other parts of the printing wheels are not subjected to any bending forces. quently, the mass of the printing wheels is reduced as compared with known constructions, which results in higher printing speed and shorter printing time.

Each printing Wheel is mounted on a support for turning movement between digital positions, and in the preferred embodiment of the invention, .all actuators and supports are turnable about a common axis. Cou-,

pling means including lost-motion means connect the actuator of each order with the support of. the sameorder, so that upon operation of each actuator, the same: first moves relative to the support, and is then coupled to the support to move with the same and with the respec-' tive printing wheel to and from the printing position. In this manner, the force required for moving the support is not transmitted through the printing wheel, but is.

will be best understood from the following descriptionof specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a fragmentary side view iliustrating a printing mechanism according to the invention in its normal initial position;

FIG. 2 is a fragmentary side view illustrating the mechanism in a printing position;

FIG. 3 is a fragmentary perspective view illustrating a detail of the printing mechanism; and

FIG. 4 is a fragmentary end view takeh in the direction of the arrow IV in FIG. 1.

Referring now to the drawings, an ordinal set of transfer wheels 2 cooperates with an ordinal set of printing wheels 1. Transfer wheels 2 are set by conventional calculator mechanism to digital positions representing digits of the respective orders, and in the transfer position shown in FIG. 1, the gear crown of each transfer Wheel 2 cooperates in meshing engagement with an outer gear 22 of the printing wheel of the same order to turn the printing wheel to a position representing the digit corresponding to the digital position of the respective Consetransfer wheel. Diametrically opposite gear segment 22, digital types 26 are secured to the rim of each printing wheel 1, each type being part of a printing portion of the segment shaped part 23 of the printing wheel. The rim of part 23 has an inner gear 24 formed of projecting locking teeth and recesses circumferentially spaced in accordance with the spacing between the types 26 and respectively associated with the digits from O to 9. FIG. 1 and FIG. 2 illustrate only one transfer wheel 2 and one printing wheel 1 in a position representing zero.

Each printing wheel has a correlated support 15 and is mounted on the respective support 15 for turning movement about a pivot pin 16. All supports 15 are mounted on a common shaft 12 which is supported in the frame, not shown, of the machine.

An ordinal set of holding members 6 is mounted on a common shaft 9 for turning movement, and a releasing member 4 is mounted for angular movement on a pin 5 of each holding member 6. A spring 7 acts on each releasing member 4 to turn the same in clockwise direction so that the free end of each releasing member 4 abuts a lateral stud 3 of the transfer wheel of the same order when the same is in the digital position representing zero. When any selected transfer wheel 2 is turned in counterclockwise direction by the calculator to set the printing wheel correlated therewith, stud 3 moves away from releasing member 4 which is turned by spring 7 to a higher position in which a shoulder 4a is located opposite a bar 8a of a cyclically operated drive means 8 which performs an angular movement about the axis of shaft 8!) and is driven from the power source of the machine by a cam 38 having a cam groove engaged by a follower pin 39 on drive means 8.

When a transfer wheel 2 has turned out of its zero position under the control of the calculator, and the respective releasing member 4 has moved up and is engaged by a bar 8a which extends across all releasing members 4 and supports 15, the respective releasing member 4 is moved in longitudinal direction to the right as viewed in FIG. 1 so that the respective correlated holding member 6 turns about shaft 9 from the position shown in FIG. 1 to the position shown in FIG. 2.

An ordinal set of actuator members 13 is mounted for angular movement on shaft 12, each actuator member 13 being associated with a corresponding printing wheel 1, a corresponding support 15, and a corresponding holding member 6. One end of each actuator member 13 is connected to a strong spring 14 which biases the respective actuating member to turn in clockwise direction. However, each actuating member 13 has a transverse projection or lug 11 which abuts a shoulder of a correlated holding member 6 in the holding position of the holding member shown in FIG. 1. When the respective holding member is turned by the respective releasing member to the releasing position shown in FIG. 2, spring 14 of the respective actuating member 13 turns the released actuating member in clockwise direction.

The other end of each actuating member is bent over as best seen in FIG. 3, and has a portion 13a disposed parallel to the main portion of actuating member 13. A spoke portion of each printing wheel is located in the thus formed space. The yoke portion of the U-shaped end of each actuating member 13 has a cutout 25 whose width is exactly equal to the thickness of the segment portion 23 and of the teeth of the inner gear 24 of the printing wheel, and serves as a locking or engaging portion cooperating with a printing wheel. Prongs 25a bound cutout 25, and are adapted to engage opposite sides of portion 23 of printing wheel 1. Each actuating member 13 has a projection formed with an abutment face 31 cooperating with a drive member 30 mounted on a lever means 37 which is cyclically reciprocated in synchronism with member 8 by cam 38 whose cam groove is engaged by a follower pin 36 on drive lever means 37.

Coupling means are provided for coupling each actuating member 13 with the associated support 15. An ordinal set of coupling members 18 is mounted for turning movement on a common shaft 20 which is supported on the frame, not shown, of the machine. Each coupling member 18 carries at its end a coupling pin 19 which is located in a slot 21 of the respective correlated actuator member 13. The diameter of pin 19 is equal to the width of slot 21, and pin 19 is slidable in the respective slot 21.

Each support lever 15 has a cutout 17 bounded by edges parallel to the longitudinal edges of slot 21 and being spaced from each other the same distance as the edges of slot 21. At the mount of cutout 17, a slanted face 17a is provided which is perpendicular to a plane passing through the axes of pin 19 and of shaft 20, and abuts pin 19 is the normal initial position of the mechanism so that no turning moment is exerted on coupling member 18 and support 15 cannot turn in clockwise direction with the respective printing wheel away from the stationary stop 28 which extends across all supports 15. In the normal initial position of the mechanism, the edges of slot 21 are transversely spaced from the edges of cutout 17, and coupling pin 19 is located outside of the respective cutout 17, constituting lost-motion means.

Shoulder 10 of each holding member 6 holds the correlated actuating member 13 in a position .in which the bottom of cutout 25 is located inwardly of the tips of the teeth of the inner gear 24 while the prongs 25a are located on opposite sides of the teeth and of segment portion 23. Consequently, the printing wheel in the transfer position shown in FIG. 1, is locked against axial movement, but free to turn about pivot pin 16 of the respective support 15.

The holding members 6 are arranged in a row, and each holding member has a lateral projection 32 crossing the foot portion 6a of the holding member of the next lower order as best seen in FIG. 4. Consequently, when any holding member 6 is moved to the releasing position shown in FIG. 2, its transverse projection 32 will turn the adjacent holding member 6 of the next lower order to the releasing position, even if the transfer wheel 2 of the respective lower order was not turned out of its zero position so that the respective releasing member of the respective lower order was not released by stud 3. This condition is illustrated in FIG. 2.

Two studs 33 are secured to each actuating member and held in place by spring rings 34. The ends of studs 33 cooperate with a correlated actuating member to exactly determine the axial spacing between each actuating member and the correlated support 15.

Operation The mechanism is shown in its normal initial position in FIG. 1. All actuating members 13 are blocked by shoulders 10 of holding members 6 against the action of springs 14. Cutout 25 of the end portion of each actuating member is positioned to permit turning of the respective printing wheel, but to prevent axial displacement of the same. Each support 15 is held by a coupling pin 19 against turning movement in clockwise direction, and abuts the common stop 29 with a shoulder 28. In this exactly determined position of the supports, each printing wheel is in a transfer position in which its outer gear meshes with the gear of the correlated transfer wheel 2 of the same order. Each transfer wheel is in a zero position in which its stud 3 holds the corresponding releasing member 4 so that spring 7 cannot move releasing member 4 into the path of movement of the cyclically operated drive means 8.

When a printing operation is started in the calculator or business machine driving the transfer wheels 2, all transfer wheels which are to represent digits different from zero are turned out of the position shown in FIG. 1 to corresponding digital positions, and the printing wheels 1 are turned correspondingly to assume digital positions in which printing portions thereof including a type 25 are respectively operative and located opposite the platen 27. In the operation illustrated in FIGS. 1 and 2, it is assumed that no digit was entered into the illustrated order, so that the printing portion including type 26 associated with the digit zero is located opposite the platen. For explanatory purposes, it may be assumed that a digit different from zero was entered into the transfer wheel 2, and that stud 3 has moved away from the corresponding releasing member 4 while the transfer wheel turned the corresponding printing wheel to a corresponding digital position.

As soon as a stud 3 moves away from a releasing member 4, spring 7 turns the same to a higher position in which the releasing member is engaged by the bar 8a of the drive means 8, and is shifted to the right as viewed in FIGS. 1 and 2 so that that the respective holding member 6 is moved from the holding position shown in FIG. 1 to the releasing position shown in FIG. 2.

Spring 14 of each released actuating member 13 will now rapidly turn the respective actuating member in clockwise direction. During such turning movement, the respective actuating member will move from its initial inoperative position shown in FIG. 1 to a locking position in which the bottom of cutout 25 will engage a locking portion of the operative printing portion formed by the bottom of a recess between adjacent locking teeth of the inner gear 23 so that the printing wheel is locked against turning movement before teeth 22 of the outer gear have separated from the gear of the respective transfer wheel 2. Consequently, the printing wheel is locked in an exactly determined precisely adjusted digital position. Each of the recesses and teeth of gear 24 is associated with a digit and if a digit other than zero was introduced by the transfer wheel into the printing wheel, cutout 25 will cooperate with a recess of gear 24 associated with the respective digit and with the printing portion of the printing wheel which includes the respective type 26.

During the movement of the actuating member from its inoperative position to its locking position, support 15 has not moved and the printing wheel remains in the transfer position meshing with the transfer wheel. During this part of the movement of the actuating member, the slanted face 17a of the respective support 15 abuts coupling pin 19. Consequently, printing wheel 1 is locked before it has started a movement to the printing position.

During further movement of an actuating member 13, the upper edge of slot 21 acts on coupling pin 19 to turn coupling member 18 about shaft 20 so that coupling pin 19 releases face 17a and engages the lower edge of cutout 17 of support 6. Further movement of actuating member 13 is transmitted by coupling pin 19 to support 6 in the position shown in FIG. 2 in which the edges of cutout 1'7 register with the edges of slot 21. From now on, actuating member 13 moves together with support 15 with which it is coupled by coupling pin 19. As a result, the respective printing wheel 1 is moved to the printing position shown in FIG. 2 while support 15 acts on the shaft of the printing wheel, while actuating member 13 acts on the respective operative printing portion of the printing wheel until the printing wheel arrives in the printing position in which the type 26 of the operative printing portion abuts platen 27 and produces an imprint under control of the support and of the actuating member. Since support, printing wheel and actuating member move simultaneously at the same speed, the bottom of cutout of the actuating member 13 remains in engagement with the bottom of the corresponding recess of the inner gear 24 so that the printing wheel remains locked against turning movement, and also locked against axial movement by the prong portions 25a. It will be understood that the printing force is directly transmitted from actuating member 13 to the operative printing portion of the printing wheel so that the pivot pin 16 on which the printing wheel is mounted for turning movement, and the spoke portions of the printing wheel are not stressed at all by the great printing force exerted by actuating member 13 directly on the operative printing portion of the printing wheel.

It will be noted that the cyclically operated drive means 8, 8a only release the mechanism, while the printing force is pr vided by the springs 14.

After all printing wheels representing digits of a multiorder number have been moved to the printing position,

. the cyclically operated lever means 37 with drive member St) is turned to the left as viewed in FIG. 2 and drive member 30 engages the abutment faces 31 of actuating members 13 which were operated during the preceding printing operation. Any engaged actuating member 13 is turned by drive member 30 in counterclockwise direction and turns the correlated support 15 through the coupling pin 19 until support 15 abuts stop means 29. When support 15 engages stop means 29, the gear portion 22 of the printing wheel meshes again with the gear of transfer wheel 2, so that a correct engagement between printing wheels and transfer wheels in accordance with the digital positions is assured before cutouts 25 of the actuating members 13 have moved out of the locking position locking printing wheels 1 against turning movement.

When support 15 abuts stop means 29, coupling pin 19 moves out of cutout 17 of support 15 and engages the slanted face 17a so that support 15 is locked, while actuating member 13 can continue its movement so that the bottom of cutout 25 moves out of the recess between adjacent teeth of gear 24 and releases the printing wheel for turning movement. Finally, the actuating members are moved against the action of spring 14 by drive member 30 to a position in which projection 11 are located above shoulders 10 of holding members 6 so that the pull of spring '7 turns the respective holding members 6 to the holding position shown in FIG. 1 in which the actuating member is again locked. Drive member 30 is now automatically moved in the opposite direction away from the actuating members.

The calculator operates in a conventional manner the transfer wheels to return to the zero position so that all printing wheels are also turned to the zero position which is possible since each actuator member 13 has moved to its inoperative position unlocking the printing wheel.

Assuming that a multi-order number has been printed, the orders of the mechanism above the highest printed order remain in zero position, and due to the fact that the releasing members 4 of such higher orders are not released by the studs 3 of the transfer wheels 2 of such higher orders, the respective actuating members are not released by the respective holding members, and no zeros are printed in the orders above the orders of the printed number.

However, in the event that the printed number contains a zero in an intermediate position, for example the number 165, it is desired to print the zero in the intermediate order, here the second order.

The transfer wheel of the highest third order is turned so that stud 3 of the highest order releases the releasing member 4, and the digit 1 is printed in the third order. Since the release of releasing member 4 in the third order permitted holding member 6 of the third order to turn from the position shown in FIG. 1 to the position shown in FIG. 2, the lateral projection 32 of the third order, which engages the holding member of the next lower second order as explained above with reference to FIG. 4, turns the holding member 6 of the next lower second order to the releasing position although the releasing member of the next lower second order was not released by the stud 3 of the transfer wheel 2 of the second order due to the fact that the second order contains the digit zero. This condition of the mechanism is illustrated in FIG. 2, in which it is assumed that the holding member 6 or" the next higher order has turned the illustrated holding member 6, although the releasing member 4 of the illustrated order was not released by the stud 3 of the transfer wheel 2 in zero position.

The printing operation in this next lower second order is carried out as above described, but since no digit was entered into the printing wheel, the printing wheel remains in the zero position and prints the zero, as desired for an intermediate order of a multi-order number.

If two successive zeros occur in two intermediate orders of a multi-order number, the holding member of the next higher order turns the holding member of the next lower order containing a zero, and the thus turned holding membar will turn the holding member of the following next lower order so that two or more zeros can be printed in intermediate order positions, although no zeros are printed in the orders above the highest order of a printed number.

It will be understood that the locking portion at the end of each actuating member will not only lock the printing wheel against turning in axial movement, but will also exactly determine the angular position of the printing wheel in which the imprint takes place so that all imprints of a multi-order number appear at the same height and precisely aligned in horizontal direction. Due to the axial locking of each printing wheel, the printed numbers of the multi-order number are exactly spaced from each other in horizontal direction.

Furthermore, the pressure of the actuating member acts directly on the operative printing portion including the respective digital type, so that only the operative printing portion is subjected to pressure, but no bending moments are exerted on the spoke portions of the printing wheel, or on the bearing of the printing wheel on the support shaft 16. As a result, the printing wheels can be made small, whereby the mass of the printing wheels is reduced, permitting faster printing operations and reducing the cost of manufacture.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of printing devices differing from the types described above.

While the invention has been illustrated and described as embodied in a printing mechanism for a business machine in which individual actuators act directly on the operative printing portions of printing wheels and lock the same, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A printing mechanism for business machines, comprising, in combination, an ordinal set of transfer wheels turnable between digital positions; a platen; a shaft; an ordinal set of supports mounted on said shaft turnable about a common axis; an ordinal set of printing wheels respectively mounted on said supports for turning movement between digital positions and having digital printing portions with locking portions, each printing wheel and correlated support having a transfer position in which the respective printing wheel cooperates with a transfer wheel to be turned between digital positions in which different printing portions are operative, and a printing position in which the operative printing portion abuts said platen and is adapted to produce an imprint; and ordinal set of actuator members mounted on said shaft for turning movement, each actuator member being movable relative to a correlated printing wheel between an inoperative position and a locking position engaging said locking portion of the respective operative printing portion for locking the correlated printing wheel in said transfer position against turning movement, and being movable in said locking position with said printing wheel to a final position for moving the same in locked condition to said printing position in which said operative portion is directly pressed by said actuating member against said platen by the correlated actuating member; coupling means including lost-motion means connecting each actuating member with the correlated support so that each actuating member first moves relative to said support from said inoperative position to said locking position and is then coupled with said support during movement to said final and printing positions so that said actuating member and said support both urge said printing wheel against said platen; and means for moving selected actuator members between said positions of the same.

2. A printing mechanism for business machines, comprising, in combination, an ordinal set of transfer wheels turnable between digital positions; a platen; a shaft; an

ordinal set of supports mounted on said shaft turnable about a common axis; an ordinal set of printing wheels respectively mounted on said supports for turning movement between digital positions and having digital printing portions with locking portions, each printing wheel and correlated support having a transfer position in which the respective printing wheel cooperates with a transfer wheel to be turned between digital positions in which different printing portions are operative, and a printing position in which the operative printing portion abuts said platen and is adapted to produce an imprint; an ordinal set of actuator members mounted on said shaft for turning movement, each actuator member being turnable about said common axis relative to a correlated printing wheel between an inoperative position and a locking position engaging said locking portion of the respective operative printing portion for locking the correlated printing wheel in said transfer position against turning movement, and being movable in said locking position with said printing wheel to a final position for moving the same in locked condition to said printing position in which said operative portion is directly pressed by said actuating member against said platen by the correlated actuating member; an ordinal set of movable coupling members, each coupling member being engaged by a correlated actuating member and being spaced in said inoperative position from the correlated support, and engaging the correlated support in said locking position of said actuating member so that each actuating member first moves relative to said support from said inoperative position to said locking position and is then coupled with said support during movement to said final and printing positions so that said actuating member and said support both urge said printing wheel against said platen and means for moving selected actuator members between said positions of the same.

3. A printing mechanism as set forth in claim 2 wherein each support has a cutout, wherein each actuating member has a slot of the same width as said cutout; and wherein each coupling member includes a pin passing through said cutout and said slot of correlated supports and actuating members, said cutout and said slot being disposed relative to each other so that each actuating member moves said pin outside of said cutout during movement from said inoperative position to said transfer position, and in said cutout during movement to said printing position.

4. A printing mechanism as set forth in claim 3 wherein said coupling members are lever arms turnable about another axis and have said pins at the ends thereof, wherein each support has at the open end of said cutout a face abutting the respective pin in said inoperative position of said actuating member in a position perpendicular to said other axis for locking the respective printing wheel and support in said transfer position; and stop means for stopping said supports in said transfer positions after a return movement from said printing position.

5. A printing mechanism for business machines, comprising, in combination, an ordinal set of transfer wheels turnable between digital positions; a platen; a shaft; an ordinal set of supports mounted on said shaft turnable about a common axis; an ordinal set of printing wheels respectively mounted on said supports for turning movement between digital positions and having digital printing portions, with locking portions each printing wheel and correlated support having a transfer position in which the respective printing wheel cooperates with a transfer wheel to be turned between digital positions in which different printing portions are operative, and a printing position in which the operative printing portion abuts said platen and is adapted to produce an imprint; an ordinal set of actuator members mounted on said shaft for turning movement, each actuator member being movable relative to a correlated printing wheel between an inoperative position and a locking position engaging said locking portion of the respective operative printing portion for locking the correlated printing wheel in said transfer position against turning movement, and being movable in said locking position with said printing wheel to a final position for moving the same in locked condition to said printing position in which said operative portion is directly pressed by said actuating member against said platen by the correlated actuating member; coupling means including lost-motion means connecting each actuating member with the correlated support so that each actuating member first moves relative to said support from said inoperative position to said locking position and is then coupled with said support during movement to said final and printing positions so that said actuating member and said support both urge said printing wheel against said platen; spring means for urging said actuator members to said locking and final position; an ordinal set of holding members, each holding member having a holding position for holding a correlated actuator memher in said inoperative position, and a releasing position, and being biased to assume said holding position; an ordinal set of releasing members respectively connected to said holding members and being biased to abut correlated transfer wheels in digital positions representing zero and to move to an operative position when the respective transfer wheel moves out of the zero position; and cyclically operating drive means engaging releasing members in said operative position for moving the correlate-cl holding members to said releasing position.

6. A printing mechanism for business machines, comprising, in combination, an ordinal set of transfer wheels turnable between digital positons and having gear portions; a platen; a shaft; an ordinal set of supports mounted on said shaft turnable about a common axis; an ordinal set of printing wheels respectively mounted on said supports for turning movement between digital positions and having digital printing portions, each printing wheel and correlated support having a transfer position in which the respective printing wheel cooperates with a transfer wheel to be turned between digital positions in which different printing portions are operative, and a printing position in which the operative printing portion abuts said platen and is adapted to produce an imprint, each printing wheel having an outer gear segment meshing with the gear portion of the correlated transfer wheel in said transfer position and an inner gear segment having digital projections and recesses respectively forming parts of said digital printing portions; an ordinal set of actuator members mounted on said shaft for turning movement, each actuator member being turnable about said common axis relative to a correlated printing wheel between an inoperative position and a locking position engaging the digital projections and recesses of the respective operative printing portion for locking the correlated printing wheel in said transfer position against turning movement, and being movable in said locking position with said printing wheel to a final position for moving the same in locked condition to said printing position in which said operative portion is directly pressed by said actuating member against said platen by the correlated actuating member; an ordinal set of movable coupling members, each coupling member being engaged by a correlated actuating member and being spaced in said inoperative position from the correlated support, and engaging the correlated support in said locking position of said actuating member so that each actuating member first moves relative to said support from said inoperative position to said locking position and is then coupled with said support during movement to said final and printing positions so that said actuating member and said support both urge said printing wheel against said platen, and so that during movement from said final position to said transfer position said actuating member remains in said locking position until said printing and transfer wheels are in meshing engagement; and means for moving selected actuator members between said positions of the same.

7. A printing mechanism for business machines, comprising, in combination, an ordinal set of transfer wheels turnable between digital positions and having gear portions; a platen; a shaft; an ordinal set of supports mounted on said shaft turnable about a common axis; an ordinal set of printing wheels respectively mounted on said supports for turning movement between digital positions and having digital printing portions, each printing wheel and correlated support having a transfer position in which the respective printing wheel cooperates with a transfer wheel to be turned between digital positions in which different printing portions are operative, and a printing position in which the operative printing portion abuts said platen and is adapted to produce an imprint, each printing wheel having an outer gear segment meshing with the gear portion of the correlated transfer wheel in said transfer position and an inner gear segment having digital projections and recesses respectively forming parts of said digital printing portions; and ordinal set of actuator members mounted on said shaft for turning movement, each actuating member having a locking portion with two prongs, each actuator member being turnable about said common axis relative to a correlated printing wheel between an inoperative position and a locking position in which said locking portion engages the digital projections and recesses of the respective operative printing portion forlocking the correlated printing wheel in said transfer position against turning movement while said prongs are located on opposite sides of said inner gear to secure the printing wheel against axial movement, each actuating member being movable in said locking position with said printing wheel to a final position for moving the same in locked condition to said printing position in which said operative portion is directly pressed by said actuating member against said platen by the correlated actuating member; an ordinal set of movable coupling members, each coupling member being engaged by a correlated actuating member and being spaced in said inoperative position from the correlated support, and engaging the correlated support in said locking position of said actuating member so that each actuating member first moves relative to said support from said inoperative position to said locking position and is then coupled with said support during movement to said final and printing positions so that said actuating member and said support both urge said printing wheel against said platen, and so that during movement from said final position to said transfer position said actuating member remains in said locking position until said printing and transfer wheels are in meshing engagement; and means for moving selected actuator members between said positions of the same.

8. A printing mechanism for a business machine; comprising, in combination, a platen; a set of printing wheels having peripheral rims, the rim of each printing Wheel having peripheral digital printing portions, each printing portion having on the outside of said rim a type face and on the inside of said rim a locking means; a set of supports supporting said printing wheels for turning movement thereon; means mounting said supports for movement with said printing wheels toward and away from said platen so that said printing wheels move to and from a printing position in which the type face of one of said printing portions cooperates with said platen; a set of actuating members having locking portions; and means for moving said actuating members to and from an operative position in which the respective locking portion directly engages said locking means of said one print-ing portion and presses the latter against said platen while locking said printing wheel against movement.

9. A printing mechanism for a business machine, comprising, in combination, printing means including a support having a pivot, and a printing wheel mounted on said pivot for turning movement between a plurality of digital positions, said printing wheel having a peripheral rim including a plurality of digital printing portions; a platen; means for mounting said support for movement to and from a printing position in which one digital printing portion is located opposite said platen; an actuating member having an engaging portion located in the region of said rim; means for moving said actuating member between a normal position in which said engaging portion is spaced from said printing wheel and an operative position in which said engaging portion engages said one printing ortion which is located opposite said platen; and coupling means for connecting said actuating member with said support in said printing and operative positions so that said actuating member and said pivot both urge said printing portion against said platen.

10. A printing mechanism for a business machine, comprising, in combination, printing means including a support having a pivot, and a printing wheel mounted on said pivot for turning movement between a plurality of digital positions, said printing wheel having a peripheral rim including a plurality of digital printing portions; a platen; means for mounting said support for movement to and from a printing position in which one digital printing portion is located opposite said platen; an actuating member having a locking portion located in the region of said rim; means for moving said actuating member between a normal position in which said engaging portion is spaced from said printing wheel and an operative position in which said locking portion engages said one printing portion which is located opposite said platen to lock said printing wheel; and coupling means for connecting said actuating member with said support in said printing and operative positions so that said actuating member and said pivot both urge said printing portion against said platen.

11. A printing mechanism for a business machine,

comprising, in combination, printing means including a support having a pivot, and a printing wheel mounted on said pivot for turning movement between a plurality of digital positions, said printing wheel having a peripheral rim including a plurality of digital printing portions; a platen and a transfer member located on opposite sides of said printing wheel; means for mounting said support for movement between a transfer position for setting said printing wheel by said transfer member to a digital position, and a printing position in which the corresponding digital printing portion is located opposite said platen; an actuating member having an engaging portion located in the region of said rim; means for moving said actuating member between a normal position in which said engaging portion is spaced from said printing wheel and an operative position in which said engaging portion engages said printing portion which is located opposite said platen; and coupling means for connecting said actuating member with said support in said printing and operative positions so that said actuating member and said pivot both urge said printing portion against said platen.

12. A printing mechanism for a business machine, comprising, in combination, a platen; a set of transfer gears; a set of printing wheels having gear portions and peripheral rims, the rim of each printing wheel having peripheral digital printing portions, each printing portion having on the outside of said rim a type face and on the inside of said rim a locking portion; a set of supports supporting said printing wheels for turning movement thereon; means mounting said supports for movement with said printing wheels toward and away from said platen between a transfer position in which said gear portions mesh with said transfer gears, and a printing position separated from said transfer gears in which printing position said type face of one of said printing portions cooperates with said platen; a set of actuating members having locking portions located inwardly of said rims and cooperating with said locking portions of said printing portions; means for moving said actuating members between an inoperative position, a locking position in which the respective locking portion directly engages said locking portion of said one printing portion for locking the respective type wheel against movement, and a printing position in which said supports and printing wheels are in said printing position; and coupling means including lostmotion means connecting each actuating member with a correlated support so that said printing wheels are separated from said transfer wheels when said actuating members are in said locking position and so that said supports and actuating members are coupled in said printing position and both act on said printing wheel.

References Cited by the Examiner UNITED STATES PATENTS 2,157,035 5/1939 Torkelson 10193 2,165,923 7/1939 Garbell 10196 2,492,263 12/1949 Boyden 101-96 2,832,283 4/1958 Vv'estinger et al. 101-93 2,951,439 9/1960 StutZ et al 10l93 FOREIGN PATENTS 532,113 8/1955 Italy.

ROBERT E. PULFREY, Primary Examiner.

WILLIAM B. PENN, Examiner.

NATHANIEL A. HUMPHRIES, Assistant Examiner. 

1. A PRINTING MECHANISM FOR BUSINESS MACHINES, COMPRISING, IN COMBINATION, AN ORDINAL SET OF TRANSFER WHEELS TURNABLE BETWEEN DIGITAL POSITIONS; A PLATEN; A SHAFT; AN ORDINAL SET OF SUPPORTS MOUNTED ON SAID SHAFT TURNABLE ABOUT A COMMON AXIS; AN ORDINAL SET OF PRINTING WHEELS RESPECTIVELY MOUNTED ON SAID SUPPORTS FOR TURNING MOVEMENT BETWEEN DIGITAL POSITIONS AND HAVING DIGITAL PRINTING PORTIONS WITH LOCKING PORTIONS, EACH PRINTING WHEEL AND CORRELATED SUPPORT HAVING A TRANSFER POSITION IN WHICH THE RESPECTIVE PRINTING WHEEL COOPERATES WITH A TRANSFER WHEEL TO BE TURNED BETWEEN DIGITAL POSITIONS IN WHICH DIFFERENT PRINTING PORTIONS ARE OPERATIVE, AND A PRINTING POSITION IN WHICH THE OPERATIVE PRINTING PORTION ABUTS SAID PLATEN AND IS ADAPTED TO PRODUCE AN IMPRINT; AND ORDINAL SET OF ACTUAOR MEMBERS MOUNTED ON SAID SHAFT FOR TURNING MOVEMENT, EACH ACTUATOR MEMBER BEING MOVABLE RELATIVE TO A CORRELATED PRINTING WHEEL BETWEEN AN INOPERATIVE POSITION AND A LOCKING POSITION ENGAGING SAID LOCKING PORTION OF THE RESPECTIVE OPERATIVE PRINTING PORTION FOR LOCKING THE CORRELATED PRINTING WHEEL IN SAID TRANSFER PORTION AGAINST TURNING MOVEMENT, AND BEING MOVABLE IN SAID LOCKING POSITION WITH SAID PRINTING WHEEL TO A FINAL POSITION OF MOVING THE SAME IN LOCKED CONDITION TO SAID PRINTING POSITION IN WHICH SAID OPERATIVE PORTION IS DIRECTLY PRESSED BY SAID ACTUATING MEMBER AGAINST SAID PLATEN BY THE CORRELATED ACTUATING MEMBER; COUPLING MEANS INCLUDING LOST-MOTION MEANS CONNECTING EACH ACTUATING MEMBER WITH THE CORRELATED SUPPORT SO THAT EACH ACTUATING MEMBER FIRST MOVES RELATIVE TO SAID SUPPORT FROM SAID INOPERATIVE POSITION TO SAID LOCKING POSITION AND IS THEN COUPLED WITH SAID SUPPORT DURING MOVEMENT TO SAID FINAL AND PRINTING POSITIONS SO THAT SAID ACTUATING MEMBER AND SAID SUPPORT BOTH URGE SAID PRINTING WHEEL AGAINST SAID PLATEN; AND MEANS FOR MOVING SELECTED ACTUATOR MEMBERS BETWEEN SAID POSITIONS OF THE SAME. 